A sample of citric acid, C6H8O7, has a mass of 22.9 g. What amount, in moles, does this mass represent?

Answer

C6H807 = 192.124 g/mol

n = m/M

n = 0.119 mol

Explanation:

to calculate amount in moles you need to find the molar mass of citric acid then divide the mass of the acid with the molar mass

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer